Method of rolling strip irons



Oct. 31, 1944.

G. ZUR NEDDEN ETAL METHOD OF ROLLING STRIP IRONS Fi led Feb. 9, 1940 I 4 Sheets-Sheet 1 Inventors G.zm- Neiien Cards Agent 1944- G. ZUR NEDDE N ET AL 2,361,729

METHOD OF ROLLING STRIP IRONS Filed Feb. 9, 1940 4 Sheets-Sheet 12 Inventors 6.2m Neohken By 5Com;

Oct. 31, 1944. G, ZUR NEDDEN ETAL 2,361,729

METHOD OF ROLLING STRIP IRONS Filed Feb. 9, 1940 4 Sheets-Sheet 3 Inventors 6.1m NedA-eu B ECWL; y Agent.

-31,1944- G. ZUR NEDDEN Em ,3 1 7 METHOD OF ROLLING STRIP IRONS Filed Feb. 9, 1940 4 Sheets-Sheet 4 Inventors G. zur Nellie? E. conch Patented Oct. 31, 1944 METHOD OF ROLLING STRIP moivs Gerhard zur Nedden and Erich Cords, Peine, near Hanover, Germany; vested in the Alien Property Custodian Application February 9, 1940, Serial No. 318,112

In Germany February 18, 1939 6 Claims.

The present invention relates to the manufacture of strip irons or strip steels provided with a projection on one surface and adapted for the production of welded I- or H-irons.

For the sake of simplicity these strip irons or strip steels are called strip iron or strip steel in the following specification.

As a rule strip irons or strip steels having the cross section of afiat rectangle and a bulb or rib at the middle of the one broad side to which a web plate is welded for instance by means of an X-seam are used for the manufacture of welded I- or H-irons. Such flat strip steels provided with a bulb or rib, however, have certain disadvantages, because often cracks were formed close to the welding seam. These cracks are due to the fact that on the one hand during welding of the neck seams the heat is conducted too fast to the thick flange profiles which at the point of welding and in the neighborhood thereof are strongly hardened and that, moreover, triaxial states of stresses occur during welding of the neck seams enhancing as is well known, separating fractures. Finally due to difiiculties in the rolling technics it is impossible ,to produce the bulb or rib of the thick bulb profiles in a manner free of objection. I

To avoid the above mentioned difficulties it has been proposed to locate the neck seams away from the cross section of the flange surface by using half broad flange irons or special T-profiles to be produced in mills for rolling shapes. If the neck seams are located in such a position, there is no danger of too fast a heat conduction and,

therefore, of a harmful hardening. Moreover,

with such vor X-seams no undesired multi-axial states of stresses occur as in connection with neck seams when using broad flange irons or special profiles which have the seams directly arranged at the flange surfaces.

In the accompanying drawings some constructions of stands and rolls for carrying out the method according to the invention are shown by way of example.

In these drawings:

Figures 1 and 2 show cross sections of ingots obtained by blooming mill trains adapted to preferably be treated in the stands illustrated in Figures 3 and 4;

Fig. 3 shows a diagrammatic front elevation of a first stand adapted for carrying out the method according to the invention;

Fig. 4 shows a front elevation of a second stand constructed as a three high stand;

Figures 5 and 6 illustrate special profiles which according to the invention may be rolled and which are provided with projections for facilitating welding of reinforcing laminations;

, Fig. 7 shows a diagrammatic front elevation of a modified construction of the first stand;

Fig. 8 shows a diagrammatic front elevation of a modification of the second stand provided with three rolls and belonging to the stand illustrated in Fig. 7;

Fig. 9 illustrates a diagrammatic front elevation of a further modification of the first stand;

Fig. 10 shows a diagrammatic front elevation of the corresponding second stand formed as a four high stand;

Fig. 11 shows the stand according to Fig. 10 with displaced lateral rolls operating then as a two high stand;

Fig. 12 shows a cross section of a preliminary profile which may further be rolled in the stands according to Figures 9 and 11', and

Figures 13 and 14 show modified constructions of the stand according to Figures 10 and 11.

The stand shown in Fig. 3 is formed as a four high or universal stand having the driven upper roll I, the driven lower roll 2 and the non-driven lateral rolls 3 and 4 (friction rolls). The latter aswell as the upper roll may be brought into position in the direction of the arrows. The rolls I and 2 are provided with circumferential grooves 5 and 6 which allow the web formed to freely pass. The second stand illustrated in Fig. 4 is provided with a driven lower roll I and with two lateral rolls 8 and 9 each inclined about an angle of about 45. The lateral rolls may be informed as friction rolls or as driven rolls which may be brought into position in the direction of the arrows shown in the drawing.

The rolling operation inthe stands shown in Figures 3 and 4 is about as follows:

In the cogging roll preliminary forming of the ingot is effected for instance by rolling down the ingot to a square cross section having a diagonal which is a little smaller than the width of the strip steel to be produced. Before the last pass is reached the ingot is edged for 45 and a cross shaped profile is produced as shown in Fig. 1. It is also possible to start with a T-shaped profile as illustrated in Fig. 4. In the latter case the lower roll I, however, has no groove 6. These preliminary profiles are pressed down in the four high stand and the three high stand in which particularly the web is treated and the rolls of which stand continuously are adjusted. After each two passes in this stand two passes in the four high stand follow to obtain clean edges of the flanges again. Special profiles such as shown for instance in Figures 5 and 6 may be produced by correspondingly profiling the rolls 8 and 9 or I, 8 and 9 respectively.

In the modifications of stands shown in Figures 7 and 8 the elements corresponding to those illustrated in Figures 3 and 4 are designated with the same reference characters. In these stands the flange surfaces are treated by the stand according to Fig. 7 the upper roll I of which is provided with such a circumferential groove that the web rolled upwardly is somewhat upset. The lateral rolls 3 and '4 serve the purpose only of guiding the rolling stock by the narrow ring discs 3a because the edges of the flange are treated by the inclined rolls of the three high stand according to Fig. 8. A loose ring Ill serves for treating the edges of the flange. The. inclined rolls 8 and 9 are, as may be seen from the drawings, composed of a plurality of parts. In this modification of the invention the web and the edges of the flange are treated in the three high standandthe surfaces of the flange in the fourhigh stand.

According to a further modification of the new method the first stand is formed as shown in Fig. 9. This stand comprises a pair of driven horizontal rolls II, I2 the lower one of which is smooth, whereas the upper one is provided with a circumferential groove I3 which has about the shape of the projection to be formed which, however, is of a greater width. The upper roll may be adjusted or be brought into position. The

width of the body of these rolls is broader than the broadest profile to be rolled.

The second stand shown in Figures 10 and 11 has a pair of driven horizontal rolls I4, I5 and a pair of non-driven vertical lateral rolls IS, IT.

The width of the body of the horizontal rolls is smaller than the smallest profile to be rolled.

spectively have the shape of the flange of the 5 projection to be formed at the strip iron or the strip steel. The lateral rolls I6. Il may be constructed in two parts in such a manner that the sections I9, 20, respectively and 2|, 22 respectively each consists of one part which for use may be .assembled by suitable means.

The rolling method using the just described stands shown in Figures 9-11 is carried out about as follows: I I

A preliminary profile 23 (Fig. 12) rolled by a preliminary roll or prepared in another manner is produced in a width substantially in accordance with the width of the final profile 24 at 'acorresponding thickness. To facilitate the later rolling the preliminary profile may already have a more or less pronounced projection 25. This preliminary profile 23 with the projection is rolled in the stand according to Fig. 9. The thickness of the preliminary profile is reduced in a plurality of passes, whereby the circumferential groove I3 of the upper roll is filled and simultaneously broadens the profile. During these passes the rolls of the stand shown in Figures 10 and 11 are moved away from'each other, the upper roll I4 is moved upwardly and the lateral rolls I6, I! outwardly, so that these rolls at the beginning are not operating. If the circumferential groove I3 is filled the stand shown in Figures I0, II operates also. The lateral rolls I6 and H are adjusted so far that a lateral upsetting of the lateral surfaces of the profile is caused by the members I9 and 20 and the flanks of the projection 25a are upset by. the members 2| and 22 of the lateral rolls. The lower sides of the members 2| and 22 of the lateral rolls I6 and H are slightly pressed upon the profile so that it may draw the lower roll I5 between the lateral rolls I6 and II. For producing this pressure the upper roll I4 may be pressed against the annular wear ledges 26, 21 of the lateral rolls I6 and I1.

The diameters of the members I9 and 20 and 2I and 22 are so chosen with respect to each other that as soon as the desired width of the profile is obtained the required thickness of the projection 25a, 25b, 250 also is obtained. During lateral upsetting roughing of the projection is effected towards the upper free side. By means of one or more passes in the stand according to Fig. 9 the roughing in the groove I3 of the upper roll I I and.

the upsetting at the projecting parts of the profile not seized in the stand according to Fig. 10 may be rolled back again. Finally in a special pass in the-stand according to Fig. 11 the projection may receive the final shape 25d necessary for welding, the lateral rolls I6 and I! being moved away from each other and the upper roll acting under slight pressure. During this operation the projection is formed by the circumferential groove I8 in the upper roll I4.

In Figures 13 and 14 the same reference letters are used to indicate corresponding elements shown in Figures 10 and 11. According to the construction shown in Fig. 13 the lateral rolls I6, I! are slightly inclined towards the interior and formed at 26 as truncated cone. The surface 26 is in contact with the upper surface of the flange. Fig. 14 shows a construction of the I lateral rolls according to which the portion 21 of the flange is not touched by the lateral rolls and freely'passes the rolls. The member 2Ilmay 1. A method for rolling steel strips of approximately inverse T-shaped cross section for use in the manufacture of welded I- and H-beams, comprising passing a preshaped blank consisting of rectangular flanges forming a base with at least one central web forming projection in upright pos tion alternately through a two-stand roll train, reducing said flanges in one of said stands independently of deforming the web projection,

and shaping the web in the other stand by lat-' eral pressure independently of further shaping the flange, said pressure exerted through adjustable lateral rolls and working the flange edges in either of said roll stands.

2. A method for rolling steel strips of approximately inverse T-shaped cross section for use in the manufacture of welded I- and H-beams, comprising passing a preshaped blank consisting of flanges forming a rectangular base with at least one central web forming projection in upright position alternately through a two-stand roll train, reducing said base forming flanges and said flange edges simultaneously in one of said stands independently of deforming the web projectlon, and then shaping the web in the second stand by a lateral pressure exerted through adjustable lateral rolls.

3. A method for rolling steel strips of approximately inverse T-shaped cross section to be used for the manufacture of welded I- and H-beams, comprising passing a preshaped blank consisting of rectangular flanges forming a base with at least one web forming central projection in upright position alternately through a two-stand roll train, reducing said base forming flanges by several successive passes through one of said stands and thereupon reducing said flanges and shaping the web independently of each'other by alternate passes through both of said roll stands.

4. A method for rolling steel strips of approximately inverse T-shaped cross section for use in the manufacture of I- and H-beams, comprising passing a preshaped blank consisting of rectangular flanges forming a base with at least one central web forming projection in upright position alternately through a two-stand roll train, reducing the thickness of said flanges and partially forming said web in one of said stands and shaping the web and simultaneousl working the flange edges in the second stand by laterritll pressure exerted through adjustable lateral ro s.

5. A method for the manufacture of steel strips of approximately T-shaped cross section for use in the manufacture of welded I and H-beams, comprising passing a preshaped blank consisting of rectangular flanges forming a base with at least one web forming central projection in upright position alternately through a two-stand roll train, reducing the thickness and broadening said base forming flanges and simultaneously partially shaping said projection by several succe'ssive passes in one of said stands, thereupon alternately working said blank in both stands and finishing shaping the web and working the flange edges in the second roll stand by lateral pressure exerted through adjustable lateral rolls, re-

moving in the first r011 stand surface irregularities formed on the noncontacted flange surfaces, withdrawing the lateral rolls of the second roll stand and finishing the blank in the latter.

6. A method for the manufacture of steel strips of approximately inverse T-shaped cross section for use in the manufacture of welded I- and H- beams, comprising passing a preshaped blank consisting of rectangular flanges forming a base with at least one web forming central projection in upright position alternately through a two-stand roll train, reducing said flanges in one of said stands and simultaneously partially shaping said web, reducing in the second stand the web and the flange edges by lateral pressure,

removing in the first stand the surface irregularities formed on the noncontacted lower flange faces and finishing the strip in the second stand by downwardly and upwardly exerted pressure.

GERHARD mm NEDDEN. ERICH CORDS. 

